The instant invention is directed to an anterior cervical tension band or surgical plate system with the capability of plates interconnecting at spaced time periods to stabilize additional vertebrae which have become diseased. This procedure is generally old and known, as is illustrated by the patent to Dinh, et al U.S. Pat. No. 7,186,254 and the publication to Bert, No. 2006/0116681. Neither of these publications recognizes or deals with the problem solved by the instant invention.
In practice, vertebrae separated by a damaged disk must be maintained, separated and be stationarily stabilized. To do this a surgical plate is positioned over a graft and secured by screws with the adjacent vertebrae. Over time, bone and cartilage may grow over, adhere to and cover the surgical plate.
It is common for the disk separating a vertebra adjacent the stabilized vertebra to break down or become diseased, i.e. up to 25% over a five-year period. When this occurs, an additional surgical plate must be installed over the two adjacent of these vertebrae.
Because of growth, as above referred to, it is extremely difficult to remove the installed plate. Further, damage to the vertebrae and surrounding soft tissue is a high probability during such a removal process.
A solution is to install an additional surgical plate adjacent the originally installed surgical plate, as illustrated by the Scharf patent No. 6,682,563. This process raises the risk of vertebra rupture due to the size of the vertebra and the many screws which are longitudinally spaced and inserted into each vertebra.
Another solution is to provide an initial surgical plate to which additional surgical plates can be attached. This arrangement is taught by the referenced patent to Dinh, et al and the publication to Bert.
Again, a problem exists. When installing the initial surgical plate, extreme care must be taken to align the connecting areas of the surgical plates with the longitudinal axis of the backbone. This is extremely difficult due to limited exposure to the entire spine, the particular anatomy or the configuration of each vertebra. It is rare that the first installed surgical plate is aligned true with the vertical axis of the spine.
When the initial plate is slightly misaligned or at a slight angle with the vertical axis, and the condition is not recognized, it can only be exacerbated by the teachings of the referenced publications. These references specifically do not allow lateral adjustment of an additional or joining plate relative to the previously installed plate.
A primary object of the invention is to accomplish segment or vertebrae fixation in a second operation without removal of the existing plate.
Another objective of the invention to provide a system of surgical plates which allow lateral adjustment of the plate being installed and attached to the previously installed plate.
Another object of the invention is a system of surgical plates which may be easily connected with the backbone and which may be easily extended along the spine without removal of initially installed plates.